For PPG flying I use generic skateboard helmet with Peltor earmuffs fitted with communication equipment. I was heavily inspired by the helmet made by SP3OTZ (website in Polish only). I have taken many photos so the construction details are clearly visible. The headset works with Baofeng UV-5R and my Kobo BlueFly variometer. After almost two years of heavy use I can tell that receiving voice quality and noise muffling is excellent. The voice transmission is more or less OK but on full throttle my voice is unintelligible. This might be probably fixed by trying different microphones and amplifiers; for now the rig suits my needs.
Earmuffs with headphones
For the headset I used Peltor Optime II earmuff suitable for hard hat mounting. They claim to reduce the noise by 31 dB and are quite spacey inside, so putting the earphone inside would not be a problem. The stock earmuff contains soft foam. I cut and removed a part of the foam to accommodate the earphone. To fix the earphone in place I used a piece of hard foam cut in the shape of the earphone. The earphone is military-grade speaker Racal 782-5393, used with Clansman radio equipment.
Push-To-Talk button is located on the left earmuff. The main cable goes to the right one which also contains the microphone amplifier. The four-wire cable goes inside the helmet from the right to the left earmuff. Two wires are used by PTT button, the other two - by the left earphone. I used cable grommets so it looks quite professional.
I took the whole microphone arm from a military headset bought in army surplus store. The original microphone was of electret kind, requiring 24 V power supply. I replaced it with noise-cancelling Racal microphone similar to Russian DMSZ1. I put a foam windscreen on it for good measure.
The electrical wiring is shown in the schematic below:
Baofeng UV-5R uses Kenwood-compatible microphone socket, with two jacks: 2.5 and 3.5 mm. The additional jack goes to my Kobo BlueFly variometer. It enables me to hear the beeps in the headset. The dynamic microphone is accompanied with one-transistor amplifier.
Modyfing the stock skateboard helmet
Warning! The manufacturer forbids modification of the helmet because it might lower its protection capabilities. You have been warned!
The helmet is a basic skateboarding helmet of Oxelo brand, bought from Decathlon. The greatest modification was the removal of the piece of the shell with the foam underneath to make space for the earmuffs. First I covered the side of the helmet with paper tape so it was easy to draw on it. Then I put the helmet on my head and looked for the optimal position of the muff. Then I marked the place for mounting hole and followed the shape of the earmuff + 15 mm. The shape was mirrored to the other side. Then I cut the shell with the Dremel multitool. I followed the advice of SP3OTZ.
The white piece of the helmet strap is 10 mm polyethylene tubing. It’s quite rigid so it goes round the earmuff. I cut it to proper length end then flatten the ends after having them heated up by the heat gun. That made them soft and easy to flatten using clamps. Then I drilled 5 mm holes in the flattened ends and riveted them to the helmet shell.
I took the strap from the aforementioned military headset. It uses velcro but in fact it holds better than the original clip strap.